Wear insert for metering system

ABSTRACT

A wear insert is provided for an air seeder metering system directing rising air away from product as it is metered from a product tank by the associated metering system. The wear insert has a lip which extends into the outlet of the metering system in order to divert air away from the path of metered product to prevent the product from bunching and to promote a continuous flow of product from the metering system.

FIELD OF THE INVENTION

The present invention relates to metering apparatus for air seeders, andmore particularly to a wear insert attachable to a seed metering systemfor directing rising air flow away from a product path. A preferredembodiment of the invention relates to a metering system having a wearinsert mounted in a meter casing for defining a volume of productmetered by a meter roller and directing rising air flow away from theproduct path and toward an air diversion path.

BACKGROUND OF THE INVENTION

Air seeders and other seeding devices are commonly towed by tractors toapply seed or fertilizer, or both simultaneously, to a field. As anexample, an air seeder may be towed in combination with a tillingimplement, one behind the other, to place the seed and fertilizer underthe surface of the soil. An air seeder has as its central component awheeled seed cart which comprises one or more frame-mounted producttanks for holding product, generally seed or fertilizer or both. Airseeders also generally comprise a metering system for dispensing productfrom the tanks and a pneumatic distribution system for delivering theproduct from tank to soil.

It is known to provide an air seeder with volumetric meters whichmeasure a fixed volume of seed per unit of linear distance. Thesevolumetric meters typically comprise either augers or fluted cylinders(meter rollers) which rotate through a product reservoir to measuregranular product, as illustrated in U.S. Pat Nos. 3,489,321 and3,763,797. The meters rotate to feed product into a pneumaticdistribution system. The pneumatic distribution system of an air seedergenerally utilizes a centrifugal fan to provide at least one airstreamwhich flows through the pneumatic distribution system to seed bootswhere product is deposited in the soil. Product is first introduced tothe air stream by the metering system at a primary distribution manifoldlocated below the metering system. Product is carried by the air streamthrough distribution lines to a series of secondary distributionmanifolds ("headers"), which in turn distribute product throughdistribution lines to seed boots mounted behind ground openers on thetilling implement so that the product may be evenly delivered to thespan of ground (the "tillage") acted upon by the tilling implement.

Operators of conventional seeding equipment often lose product to thetillage while the metering system is not operating, due to forces actingupon the product above the meter, including gravity and a lower pressureair stream running below the meter. The large central product tanks ofan air seeder may lose substantial amount of product. One method ofpreventing lost product includes the use of a device to shut off flow ofproduct between a product tank and a meter. For example, U.S. Pat No.4,834,004 discloses slides which may be used to shut off product to ametering system. However, some amount of product may still be lost afterthe meter is shut off and before the shut-off device is actuated. Inaddition, operators must remember to actuate the shut-off device eachtime a meter is stopped.

In addition, if the product tank above the meter is not pressurizedproperly, the pressure in the product tank may be lower than thepressure of the air flowing through the pneumatic distribution systembelow the meter. In such a case, product may attempt to flow from thepneumatic distribution system through the meter and into the producttank, even while the meter is running. Even momentary occurrences ofthis condition can prevent product from flowing smoothly into thepneumatic distribution system and instead causes the product to bunchand pulse as it leaves the meter.

Therefore, it is desirable to devise a metering system having amechanism to prevent air from the pneumatic distribution system fromsubstantially affecting metering of product while the air flows throughthe metering system in reverse. It is also desirable to devise such amechanism which may be replaced with relative ease.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an improvedmechanical metering system for metering product.

It is an additional object of the present invention to devise a wearinsert for a metering system which directs rising air away from productas the product is metered.

It is a further object of the present invention to provide a wear insertcapable of preventing product from bunching and helping to define thevolume of product metered from the product tank to the pneumaticdistribution system by the meter rollers, while not impeding accurateand continuous metering by the meter rollers.

According to the invention the objects are attained by providing a wearinsert for a metering system disposed between a product tank and aprimary distribution manifold of a pneumatic distribution system. Thewear insert extends into the metering system's outlet to direct air flow(due to underpressurization of the product tank) away from a productpath as product is metered.

The preferred embodiment of the present invention provides a urethanewear insert which is fixed in a meter casing so that a lip of the wearinsert extends into the outlet of the meter casing for diverting airaway from product as the product is metered. The width of the wearinsert determines the distance between an inner wall of the meter casingand the meter roller, thus helping determine the volume of productmetered.

In the following description the invention is explained in greaterdetail on the basis of a preferred embodiment with reference to thedrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a left side elevational view of an air seeder constructedaccording to a preferred embodiment of the present invention.

FIG. 2 is a left side elevational view of the air seeder of FIG. 1towing a tilling implement.

FIG. 3 is a left side perspective view of a metering system constructedaccording to a preferred embodiment of the present invention.

FIG. 4 is a right side perspective view of a metering system constructedaccording to a preferred embodiment of the present invention.

FIG. 5 is an exploded perspective view of a meter cartridge.

FIG. 6 is a perspective view of a meter housing and meter cartridge, themeter cartridge removed from the meter housing.

FIG. 7 is a cross sectional view of a metering system and a primarydistribution manifold.

FIG. 8 is an exploded view of a right end plate of a meter housing andan agitator shaft.

FIG. 9 is an exploded view of a product disconnect.

FIG. 10 is an exploded isometric view of a meter roller and blanksection according to a preferred embodiment of the present invention.

FIG. 11a is a side view of a wear insert according to a preferredembodiment of the present invention.

FIG. 11b is a perspective view of the wear insert of FIG. 11a.

FIG. 12a is a side view of a meter roller brush according to a preferredembodiment of the present invention.

FIG. 12b is a perspective view of the meter roller brush of FIG. 12a.

FIG. 13 is an exploded view of a plenum according to a preferredembodiment of the present invention.

FIG. 14 is a perspective view of a primary distribution manifoldaccording to a preferred embodiment of the present invention.

FIG. 15 is a partially exploded view of the primary distributionmanifold of FIG. 14.

FIG. 16a is a perspective view of a left bypass port half according to apreferred embodiment of the present invention.

FIG. 16b is a top view of the left bypass port half of FIG. 16a.

FIG. 16c is a side view of the left bypass port half of FIG. 16a.

FIG. 16d is a sectional view of a left bypass port half taken along lined--d in FIG. 16c.

FIG. 17a is a perspective view of a right venturi port half according toa preferred embodiment of the present invention.

FIG. 17b is a top view of the right venturi port half of FIG. 17a.

FIG. 17c is a side view of the right venturi port half of FIG. 17a.

FIG. 18 is an exploded view of a manifold adjustment mechanism accordingto a preferred embodiment of the present invention.

FIG. 19 is a plan view of an air seeder in a tow-behind configurationaccording to an alternate embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

An air seeder constructed according to a preferred embodiment of thepresent invention is shown in FIGS. 1-18. With reference to FIGS. 1-2,an air seeder is shown comprising a seed cart 5 towed between a tractor(not shown) and a tilling implement 10. The seed cart 5 has a frame 15to which product tanks 20 and wheels 25 are mounted. Each product tank20 has an associated metering system 30 at its lower end for controlledfeeding of product into a pneumatic distribution system 35 at a primarydistribution manifold 40. The tilling implement 10, towed behind theseed cart 5, consists generally of a frame 45 to which ground openers 50are mounted. Incorporation of seed row finishing equipment such aspackers 55 is also desirable in many applications.

Referring now to FIGS. 3-7, one of the metering systems 30 of thepresent invention is shown comprising a meter housing 60 which surroundsa product disconnect 65 and a meter cartridge 70. The meter housing 60comprises a top plate 75 which has a product entrance slot 80, front andrear side panels 85, 90, left and right end plates 95, 100, and hingedcleanout doors 105, having door seals 107 (FIG. 9), on the front sidepanel 85. The left end plate 95 is provided with a cartridge removalopening 110. The top plate 75 connects the front and rear side panels85, 90 and left and right end plates 95, 100 to form a productdisconnect chamber 115, a product cleanout chamber 120, and a meterchamber 125 with product discharge slots 130 at its lower end.Preferably, there is a product discharge slot 130 for each run in theprimary distribution manifold 40.

The meter cartridge 70 is housed in the meter chamber 125. Referring nowto FIGS. 5 and 6, the meter cartridge 70 is shown comprising a casing135, consisting of a plurality of casing sections 140 and a series ofmeter rollers 145. Preferably, one meter roller 145 and one casingsection 140 are provided for each run in the primary distributionmanifold 40. The meter rollers 145 are rotatably mounted in the casing135, and rotate with a meter drive shaft 150. The casing sections 140comprise a wear insert 155, a meter roller brush 160, and, whendisabled, a door insert 165. The casing sections 140 are held togetherby cartridge rods 170 which extends through the casing sections 140.Each of the casing sections 140 is provided with a casing inlet 175 forreceiving product and a casing outlet 180 for dispensing product. Inaddition, casing sections 140 each have a wall 142 to isolate eachcasing section 140 from an adjacent casing section 140.

A handle 194 is mounted to an end of the meter cartridge 70 to assistthe operator in removing the cartridge. The meter cartridge 70 isremovable from the meter chamber 125 by releasing an over center cam 185mounted to the meter housing 60, rotating the meter cartridge 70 todisengage the meter cartridge 70 from seals 190 within the meter housing60, and sliding the meter cartridge 70 out of the meter housing 60. Themeter cartridge 70 may then be replaced or reconfigured to a differentsetting corresponding to the setup of the tilling implement 10 and thetype of product to be metered from the product tank 20. The operator canreplace the meter cartridge 70 by sliding the meter cartridge 70 intothe meter chamber 125, rotating the meter cartridge 70 until itencounters a cartridge positioning stop 195 in the meter housing 60, andengaging the over center cam 185, which assists the operator in rotatingthe meter cartridge 70 and locks the meter cartridge 70 in an engagedposition against the seals 190.

The metering systems 30 are preferably ground driven so thatsubstantially the same amount of product is applied per unit of lineardistance despite variations in tractor speed. Referring now to FIG. 1, asprocket 200, driven by one of the wheels 25 through a right angle gearbox 202, is coupled by a chain 205 to a main drive shaft sprocket 210.The main drive shaft sprocket 210 is ratcheted to a main drive shaft 215so that the main drive shaft 215 rotates only as the wheel 25 rotates inthe direction corresponding to forward movement of the seed cart 5. Themain drive shaft 215 is coupled to a ratio box 220 corresponding to eachmetering system 30. The ratio box 220 enables an operator to vary therate of rotation of a transverse shaft 225 (seen in FIG. 3) with respectto the rate of rotation of the main drive shaft 215. The transverseshaft 225 driven by the ratio box 220 is in turn coupled to a transverseshaft sprocket 230 (seen in FIG. 4), which is connected by a meter drivechain 235 to a meter drive sprocket 240. The drive sprocket 240 ismounted on a short shaft 241 which has a drive fitting 246 mounted onthe end opposite from the sprocket 240. the meter drive fitting 246 andmeter drive 245 each has a pair of tapered fingers which extend parallelto the axis of rotation of their respective shafts and the fingers ofeach engage the fingers of the other. The meter drive shaft 150, whichextends through the meter rollers 145 in the meter cartridge 70, isconnected to the meter drive fitting 246 by a meter drive 245, causingthe meter rollers 145 to turn (and meter product) as the seed cart 5travels forward and the wheel 25 rotates.

Referring now to FIG. 8, one end of an agitator drive 250, comprising apitman 252 and a crank 254, is fixed off-center to the meter drivesprocket 240 and secured at the other end to an agitator shaft 255,causing the agitator shaft 255 to oscillate about its axis as the meterdrive sprocket 240 revolves. Agitator pins 260 extend through theagitator shaft 255 and engage product within the product disconnectchamber 115 to prevent the product from bunching together and toencourage steady product flow.

Although the preferred embodiment uses a combination of shaft and chaindrives, other methods of transferring power are known to those skilledin the art.

Referring now to FIGS. 6 and 9, the product disconnect 65 is rotatablysecured in the product disconnect chamber 115 by the left and right endplates 95, 100 of the meter housing 60. The product disconnect 65comprises a pair of rotary cutoff valves 265 and a product disconnecthandle 270 connected to each rotary cutoff valve 265. At their interiorends, the rotary cutoff valves 265 abut cutoff valve bearings 269 whichare fixed in the housing 60. A handle locator guide 267 is fixed betweenthe product disconnect handles 270 to enable an operator to easilydetermine whether each product disconnect handle 270 is in an openposition or a closed position. A flexible seal 192 is mounted to themeter housing 60 between the meter chamber 125 and the product cleanoutchamber 120. The agitator shaft 255 (shown in FIGS. 7, 8) extendsthrough the rotary cutoff valves 265 along the axis of rotation of therotary cutoff valves 265. By raising the product disconnect handles 270,rotary cutoff valves 265 are rotatable from the open position, allowingproduct to pass into the meter chamber 125, to the closed position,which shuts off passage of product into the meter chamber 125 andinstead directs product to the product cleanout chamber 120. Therefore,an operator can place the rotary cutoff valves 265 of the productdisconnect 65 in their closed position, remove the meter cartridge 70from the meter housing 60 and reconfigure meter rollers 145 or replacethe meter cartridge 70 with another meter cartridge 70 pre-configuredfor a desired seeding plan.

Use of two rotary cutoff valves 265, each extending half the width ofthe product entrance slot 80 of the meter housing 60, allows theoperator to disconnect none, half or all of the metering system 30 fromthe product tank 20 above the product disconnect 65. Additional rotarycutoff valves 265 may be incorporated to enable disconnection of smallerportions of the width of the metering system 30 (for instance, eightrotary cutoff valves 265 could be used across the width of the meteringsystem 30 in the present example, each rotary cutoff valve 265representing one meter roller 145 and one run in the pneumaticdistribution system 35.

Referring now to FIG. 10, the meter roller 145 according to the presentinvention is shown having a series of ridges 275 defining productreceiving valleys 280. The meter roller 145 has a product carryingvolume equal to the sum of volumes of the product receiving valleys 280.Additionally, the meter roller 145 has a hexagonal bore 285.

Although the meter rollers 145 may be made of virtually any material, aurethane plastic is preferable, and compound No. GC3501 durometer 90 R+/-5 impact modified 66 nylon is the most preferred material for themeter rollers 145. If the meter rollers 145 are made of urethane,thermal expansion during operation may present unnecessary friction andwear of components of the metering system 30. Therefore, an axialretainer shaft 290 with a hexagonal outer surface conforming to thehexagonal bore 285 of the meter roller 145 is preferably provided. Theaxial retainer shaft 290 is constructed of material having a lowercoefficient of thermal expansion than the material making up the meterroller 145. Preferably, the axial retainer shaft is constructed ofGC3280 80D+/-5 40% glass and mineral polyester polyurethane. The axialretainer shaft 290 has a hexagonal retainer shaft bore 295 for receivingthe meter drive shaft 150. The axial retainer shaft 290 extends throughthe meter roller 145 and is provided at its ends with bearing plates 300which abut the meter roller 145 and are fixed to the axial retainershaft 290 by snap rings 305. Preferably the axial retainer shaft 290 isprovided with bearing plate engagement pegs 310 which extend intocorresponding notches 315 in the bearing plates 300 so that each bearingplate 300 rotates with the meter roller 145 it is abutted against,preventing heat and wear caused by excess friction. The casing section140 which abuts the bearing plate 300 on the side opposite the meterroller 145 and does not rotate with the bearing plate 300, should beconstructed of a material which exhibits a low coefficient of frictionand good wear characteristics, preferably GC3240 121R +/-5 40% glass andmineral filled nylon 6 heat stabilized.

To reduce the amount of product metered by a meter roller 145 (andtherefore, the amount of product delivered by distribution lines 320 toa downstream secondary distribution header 325 on the tilling implement10), a blank section 330 may be added to the meter roller 145. Referringnow to FIG. 10, the blank section 330 may be placed over the meterroller 145 to occupy space in the product receiving valleys 280 of themeter roller 145. The blank section 330 is slid axially along the roller145 to the center of the roller 145 for optimal product flow.Preferably, holding ribs 335 extend radially inward from an interiorsurface 340 of the blank section 330 to engage the meter roller andprovide additional friction to keep the blank section 330 from movingaxially along the meter roller 145 after the blank section 330 ispositioned. Various size blank sections 330 may be used depending on theamount of space to be occupied, but preferably the blank section 330conforms to the cross-section of the meter roller 145 (meter rollers 145have varying cross sections and product carrying volume, generallyselected based on the product to be metered).

Referring now to FIGS. 7, 11a and 11b, the wear insert 155 is fixed ineach of the casing sections 140 below the meter roller 145. The wearinsert 155 includes fastening protrusions 345 which snap intocorresponding dovetail notches 350 in an internal wall 355 of casingsection 140 to provide a friction fit within the casing section 140.Preferably, the casing section 140 is provided with a wear insert step360 so that product may more easily flow along the inner wall 355 of thecasing section 140 over the wear insert 155 and through the casingoutlet 180. The thickness of the wear insert 155 may be varied to affectthe distance between the wear insert 155 and the meter roller 145, thusaffecting the rate at which product is metered from the metering system30. The wear insert 155 has a lip 365 which extends partially over thecasing outlet 180, thereby directing rising air flow away from productbeing metered and toward the urethane meter roller brush 160. The wearinsert 155 may be removed and replaced when worn or when the operatorwishes to alter the characteristics of the metering system 30.

Referring now to FIGS. 7, 12a and 12b, the meter roller brush 160 ismounted in each casing section 140, extending between the inner wall 355of the casing section 140 and the meter roller 145. The meter rollerbrush 160 is removably fixed to the casing section 140 by sliding themeter roller brush 160 into the casing section 140 so that L-shaped tabs380 in the casing section 140 engage a top face 370 of a meter rollerbrush base 375. The meter roller brush 160 has a plurality of bristles385 extending from the meter roller brush base 375 for providing abarrier that product can't pass through, while allowing air to pass.Preferably, the bristles 385 have varying rake angles, beginning at 5-10degrees at each side and converging. The meter roller brush 160increases metering accuracy by preventing product from flowing upthrough the meter cartridge 70, as it is prone to do when air pressurein the product tank 20 above is too low.

The pneumatic distribution system 35 includes a centrifugal fan 390which is connected to a plenum 400, which is in turn connected bydistribution lines 320 to one or more primary distribution manifolds 40,each associated with a product tank 20. The primary distributionmanifolds 40 are connected by distribution lines 320 to a dimpled risertube 405 which is coupled to one of the secondary distribution headers325. Distribution lines 323 connect the secondary distribution header325 to seed boots 410 mounted on the ground openers 50.

The pneumatic distribution system 35 is shown as having generally tworows of distribution lines 320 and ports in the primary distributionmanifold 40, representing separate air streams such that the productfrom separate product tanks 20 are not commingled as they are carriedpneumatically from the product tanks 20 to the tillage. This arrangementis commonly referred to as "double shoot". Alternatively, the pneumaticdistribution system 35 may be configured as a singular air stream whereonly one product tank 20 is involved or products from separate producttanks 20 are commingled as they are delivered to the tillage. Such aconfiguration is referred to as "single shoot." The single shootconfiguration would require only half the distribution lines 320 andsecondary distribution headers 325, and only one row of ports on theprimary manifold(s) 40.

The air seeder is also adaptable to a triple-shoot configuration byadding another product tank 20' as shown in FIG. 19, and an additionalair stream (an additional set of distribution lines 320', secondarydistribution headers 325 and seed boots 410, as well as another row ofports in the primary distribution manifolds 40').

Referring now to FIG. 13, to create two generally separate air streamsin the double shoot configuration, air from the centrifugal fan 390 ispassed through the plenum 400, where a plenum damper 415 directs adesired proportion of air to upper and lower rows of plenum output ports420, such that each plenum outlet port 420 in a row has substantiallythe same amount of air flowing through it. The plenum damper 415 isfixed in the plenum 400 by a threaded damper shaft 425 threaded throughan internally threaded sleeve 426 fixed in the plenum damper 415. Adamper shaft crank 430 is connected to the damper shaft 425 so as thedamper shaft crank 430 is turned, the damper shaft 425 rotates and theplenum damper 415 may be raised or lowered to provide the desired amountof air to each row of plenum output ports 420. A plenum damper guide rod427 and sleeve 428 extend through the plenum damper 415 to prevent theplenum damper 415 from rotating as it is raised or lowered.

Each column of plenum output ports 420 and associated downstreamdistribution lines 320 represents a "run", and corresponds to placementof product at a particular portion of the width of the tillage. Adistribution line 320 is connected to each plenum output port 420 in useby a hose clamp 435. Plenum outlet ports 420 for runs not in use areclosed off by caps 440. The air seeder shown in the appended Figures isin an eight run, double shoot configuration.

Referring now to FIGS. 14-15, the primary distribution manifolds 40 inan eight-run, double shoot configuration are each made up of eightcolumns and two rows of manifold ports, one row having eight venturiports 445 and having a venturi pressure plate 450 at each end of therow, and another row having eight bypass ports 455 and a transferpressure plate 460 at each end of the row. Manifold nozzles 465 arepositioned at the front and rear of each of the venturi ports 445 andthe bypass ports 455. A cover 470 may be used to deny product to one ofthe venturi ports 445 or one of the bypass ports 455 when a runassociated with that port is not in use.

Referring now to FIGS. 15-16d, the bypass ports 455 are made up of leftand right bypass port halves 475, 480. The left and right bypass porthalves 475, 480 are identical molded pieces which are positionedopposite each other to form the bypass port 455, which comprises aproduct throughway 485, a bypass inlet 490 and a bypass outlet 495.Referring now to FIGS. 15, 17a-17c, the venturi ports 445 are made up ofleft and right venturi port halves 500, 505, which are mirror images ofeach other and are positioned against each other to form the venturiport 445 having an air passage 510 and a product inlet 515. The airpassage 510 in the venturi port 445 preferably constricts from a mainventuri port air inlet 520 having a diameter 2.5 inches to a diameter of1.9685 inches (50 millimeters) at a venturi 525 below the product inlet515 to provide a desired pressure reduction for optimal flow of productfrom the meter housing 60 into the primary distribution manifold 40.Downstream from the product inlet 515, the air passage 510 expands froma 1.9685 inch diameter to a 2.5 inch diameter at a main venturi portoutlet 530. A rounded edge 535 at the downstream side of the productinlet 515 improves product flow and reduces damage to product as itenters the venturi port 445.

Rows of the bypass ports 455 and the venturi ports 455 are held togetherand positioned on a manifold support plate 540 by a pair of manifoldrods 545 which extend through the manifold nozzles 465.

The venturi pressure plates 450 have a nozzle-side orifice 550 and ameter-side orifice 555 and are secured to the ends of rows of venturiports 445 by screws 560. The transfer pressure plates 460 have a lowertransfer orifice 565 and an upper transfer orifice 570 and are similarlyattached to each end of a row of the bypass ports 455 by screws 560.

The left and right bypass port halves 475, 480 are held together byinterlocking tabs 575 on the left and right bypass port halves 475, 480and on the manifold nozzle 465 which is slid over the left and rightbypass port halves 475, 480. The manifold nozzles 465 are two rows highin the double shoot configuration and similarly engage interlocking tabs575 on the left and right venturi port halves 500, 505 on the row of theprimary distribution manifold 40 made up of the venturi ports 445.

Referring now to FIGS. 15 and 18, on a side each of the manifold nozzles465 opposite the interlocking tabs 575, a tapered slot 580 is providedfor accommodating a face side 585 of a manifold nozzle seal 590. In thedouble shoot configuration, two rows of tapered slots 580 are providedwhich are offset (shown in FIGS. 7, 14, 15 and 18). The manifold nozzleseals 590 extend through openings 592 in a manifold conduit support 595mounted to the frame 15, and are coupled at their tube sides 600 todistribution lines 320.

Preferably, various orifices in transfer pressure plates 460, venturipressure plates 450 and manifold nozzles 465 are screened to keepproduct from entering.

Each product tank 20 is pressurized by air from the centrifugal fan 390.The meter housing 60 is provided with an air passage 605 (shown in FIG.7) for directing pressurized air from the air stream in the primarydistribution manifold 40, upstream from the venturi 525, to hollow legs610 of the product tank ladder 615 (shown in FIGS. 1 and 7), which inturn conduct the pressurized air to the product tank 20 above the meterhousing 60. This results in substantially equal pressure above and belowthe product, urging the product to enter the underlying air stream ofthe pneumatic distribution system 35. However, the product tank 20 mustbe sealed correctly during operation to assure accurate product deliveryand to avoid "pulsing," an undesirable condition where product isdelivered in disjointed batches rather than in a more continuous flow.

Referring now to FIG. 18, in the preferred embodiment of the invention,the primary distribution manifold 40 is situated on a rectangularmanifold support frame 620. At each corner of the manifold support frame620 is fixed an internally threaded cylinder 625. A threaded verticalmanifold adjustment shaft 630 having a beveled gear 635 at its upper endis threaded through each internally threaded cylinder 625 and extendsthrough vertical bushings 640 mounted to the manifold conduit support595. The four beveled gears 635 each engage one of four further beveledgears 645. The further beveled gears 645 are fixed at opposite sides oftwo transverse manifold adjustment shafts 650. The transverse manifoldadjustment shafts 650 extend through transverse bushings 655 fixed tothe manifold conduit support 595 and are each also provided with a rearsprocket 660 fixed to an end of the transverse manifold adjustment shaft650. The two rear sprockets 660 are connected by a chain 665, and amanifold adjustment crank 670 is fixed to an end of one of thetransverse manifold adjustment shafts 650 opposite the rear sprocket660.

When the manifold adjustment crank 670 is turned, the transversemanifold adjustment shaft 650 to which the manifold adjustment crank 670is fixed rotates, and the beveled gears 635, 645, the rear sprockets 660and the chain 665 comprise a manifold adjustment mechanism 667 whichproduces substantially uniform rotation of the vertical manifoldadjustment shafts 630 causing the primary distribution manifold 40 andmanifold support frame 620 to be raised or lowered evenly. Duringoperation, the primary distribution manifold 40 is maintained in a fullyraised, engaged position. When the primary distribution manifold 40 islowered from its engaged position, manifold nozzles 465 slide away fromcontact with manifold nozzle seals 590, which maintain their position inthe manifold conduit support 595. When the primary distribution manifold40 is lowered, it may be slid from the manifold support frame 620 forcleaning and/or replacement. When the primary distribution manifold 40is raised into its engaged position, the manifold nozzle seals 590 areguided by the tapered slots 580 of the manifold nozzle 465 to form asubstantially airtight connection from the primary distribution manifold40 to upstream and downstream distribution lines 320. In the doubleshoot configuration, top and bottom rows of the openings 592 in themanifold conduit support 595 are offset, conforming to a matching offsetin the tapered slots 580 of the manifold nozzle 465. This offset allowsthe top row of tapered slots 580 to engage only the top row of manifoldnozzle seals 590, and the bottom row of tapered slots 580 to engage onlythe bottom row of manifold nozzle seals 590 as the primary distributionmanifold 40 is raised into its engaged position.

Next, the operation of an air seeder incorporating the preferredembodiment of the present invention will be discussed in greater detail.

During operation of the metering system 30, product is drawn (by gravityand low pressure airflow through the venturi ports 445) from the producttank 20 into the meter housing 60 through the product entrance slot 80into the product disconnect chamber 115. While in the product disconnectchamber 115, product is prevented from bunching together by the agitatorpins 260 of the agitator shaft 255 which rotates through the product inthe product disconnect chamber 115.

If one of the rotary cutoff valves 265 is in a closed position, productencountering the rotary cutoff valve 265 is prevented from passing intothe meter chamber 125 and is instead directed to the product cleanoutchamber 120. Therefore, meter rollers 145 and runs serviced by therotary cutoff valve 265 are denied product and essentially no productfrom the product tank 20 will be delivered to the tillage by thedisconnected runs. If both of the rotary cutoff valves 265 of theproduct disconnect 65 are in their closed position, substantially all ofthe product is prevented from entering the meter chamber 125 andessentially no product from the product tank 20 will be delivered to thetillage. Instead, product is diverted to the product cleanout chamber120, and the operator can open the cleanout doors 105 to empty theproduct tank 20 without sending product through the remainder of themetering system 30.

If both rotary cutoff valves 265 are in their open position, productwill pass into the meter chamber 125 and enter the meter cartridge 70through the casing inlet 175. The rotational speed of the meter rollers145 may be varied in order to achieve a desired seed rate. Byadjustments at ratio boxes 220 to change the rate of rotation of thetransverse shaft 225 relative to main drive shaft 215, meter rollers 145in metering systems 30 for separate product tanks 20 can be driven atdifferent rates. As the meter rollers 145 rotate they carry product intheir product receiving valleys 280 to the casing outlet 180, where theproduct is drawn into an air stream at the primary distribution manifold40. Product is prevented from flowing upward through the casing 135 bythe meter roller brushes 160 and the wear inserts 155.

Meanwhile, the centrifugal fan 390 is driven by the tractor's hydraulicsystem (not shown), forcing pressurized air through the pneumaticdistribution system 35. Air travels from the centrifugal fan 390 to theplenum 400, where air is diverted by the plenum damper 415 through theplurality of plenum output ports 420. The distribution lines 320 carrythe air to a primary distribution manifold 40.

When product from the product tank 20 above the primary distributionmanifold 40 is to be deposited in the top row of ports, venturi ports445 are used to make up the top row of ports in the primary distributionmanifold 40, with venturi pressure plates 450 at the sides of the toprow. Product is metered into the primary distribution manifold 40 at theproduct inlet 515. Some of the pressurized air from the pneumaticdistribution system 35 is taken in the top row of ports just before theventuri 525 by a tank pressure orifice 675 (shown in FIG. 15) in theoutermost manifold nozzles 465 (those adjacent to the venturi pressureplates 450) to the venturi pressure plates 450 at the end of the toprow. The air enters the venturi pressure plate 450 at the nozzle-sideorifice 550 and is conducted to the meter-side orifice 555, where itpasses into the meter housing 60. Air is then conducted through airpassage 605 of the meter housing 60 into hollow legs 610 of the producttank ladder 615 mounted above the meter housing 60. Finally, the aircarries to top of the product tank ladder 615 where it is dispensed intothe product tank 20.

When product from the product tank 20 above one of the primarydistribution manifolds 40 is to be deposited in the bottom row of ports,bypass ports 455 are used to make up the top row of ports in the primarydistribution manifold 40, with transfer pressure plates 460 at the sidesof the top row. Product is metered into the primary distributionmanifold 40 at the bypass inlets 490 of the bypass ports 455, where itis diverted around the product throughways 485 and falls through thebypass outlets 495 into the product inlets 515 of the bottom row venturiports 445. Some of the pressurized air from the pneumatic distributionsystem 35 is taken by tank pressure orifices 675 in the outermostmanifold nozzles 465 on the bottom row. The air is carried to theventuri pressure plate 450 at the end of the bottom row. The air entersthe venturi pressure plate 450 at the nozzle-side orifice 550 and exitsat the meter-side orifice 555, where it is conducted into the transferpressure plate 460, entering at the lower transfer orifice 565 andexiting at the upper transfer orifice 570. Air passes from the uppertransfer orifice 570 into the meter housing 60, continues through theair passage 605, through the legs 610 of the product tank ladder 615 andinto the product tank 20.

Air and product flow in the pneumatic distribution system 35 from theprimary distribution manifold 40 through distribution lines 320 to thedimpled riser tubes 405 which attempt to randomize distribution ofproduct from the secondary distribution headers 325 which areimmediately downstream. The secondary distribution headers 325 dividethe product substantially evenly into a series of the distribution lines323 leading to the seed boots 410 on the ground openers 50 where productis delivered to the tillage.

To change placement of product in soil without reconfiguring downstreamdistribution lines, an operator can place the product disconnect 65 inits closed position so that no product will be metered. The operator canthen exchange primary distribution manifolds 40 such that product from aparticular product tank enters the primary distribution manifold 40 at adifferent row of venturi ports 445 or bypass ports 455, and is carriedby distribution lines 320 to the tillage at a different location. Forexample, if product is replaced with a larger grain to be metered, anoperator can remove the meter cartridge 70 and replace it with aseparate meter cartridge 70 with meter rollers 145 having larger productreceiving valleys 280. If instead an operator switches from anapplication where more fertilizer is needed than seed to an applicationwhere more seed is needed than fertilizer and one of the product tanks20 is larger than the other, the operator can reduce the number of stopsrequired to fill product tanks 20 by removing the primary distributionmanifolds 40 below the product tanks 20 and exchanging them to reversethe location of venturi ports 445 and bypass ports 455. This exchangeresults in seed and fertilizer placed at the same location in thetillage as they were in the previous application without having toreconfigure distribution lines 320.

If, however, the operator wishes to change the width of the tillage orhas changed the setup of the tilling implement 10, the operator can shutoff one or more runs by placing caps 440 on a column of plenum outputports 420, inserting the door insert 165 into the casing inlet 175 tocut off the casing section 140 associated with the run, and placing acover 470 on the product inlet 515 of the venturi port 445 or over thebypass inlet of the bypass port 455 (whichever is located in the top rowof ports in the primary distribution manifold 40). If the number of seedboots 410 serviced by the metering system 30 and the pneumaticdistribution system 35 has been reduced but still require the samenumber of runs, the operator can remove one or more of the metercartridges 70 and replace them with meter cartridges 70 preconfiguredfor the setup of the tilling implement 10, or can reconfigure the metercartridges 70 by adding blank sections 330 to one or more meter rollers145 to reduce the capacity an individual run.

Preferably, the air seeder is equipped with a platform 680 (shown inFIG. 2) for the operator to stand on when loading product into theproduct tanks 20 and inspecting the product tanks 20.

Also, an electronic seed monitor of known design (not shown) may beincluded to warn the operator if one of the seed boots 410 is plugged,warn the operator if product level in one of the product tanks 20 islow, and calculate the number of acres seeded. A tone wheel 196 (shownin FIG. 3) may be helpful to monitor the rate of rotation of the meterrollers 145 in one of the metering systems 30.

In addition, an auger 685 of known design (shown in FIG. 1) may bemounted to the seed cart 5 for conveying product to the product tanks 20and for conveying unused product from product tanks 20.

Referring now to FIG. 19, although the invention is discussed in termsof a preferred embodiment configured as a "tow-between" air seeder, theinvention also contemplates a "tow-behind" arrangement in which the seedcart 5' is towed behind the tilling implement 10. The air seeder in a"tow-behind" arrangement includes additional casters 690 at the frontend of the seed cart 5' to support load which is transmitted to thetractor through the tongue of the seed cart in the "tow-between"configuration. The operation of the air seeder in the "tow-behind"arrangement is substantially similar to that of the "tow-between"configuration; however, components are reversed such that the pneumaticdistribution system 35' moves air and product from the rear of the seedcart 5' forward so that product is delivered to seed boots 410 on thetilling implement 10 in front of the seed cart 5'.

Further advantageous embodiments are given by the subordinate claims.

What is claimed is:
 1. A metering system for metering product in an airseeder having a product tank and a pneumatic distribution system, saidmetering system comprising:a meter casing having an inner wall, an inletcoupled to the product tank and an outlet coupled to the pneumaticdistribution system such that the meter casing provides a substantiallyenclosed passage between the pneumatic distribution system and theproduct tank; a meter roller rotatably mounted in the casing; aplurality of open volumes between the meter and the inner wall of thecasing connecting the inlet and the outlet, said plurality of openvolumes including a product path for metering product from the inlet tothe outlet and an air diversion path for permitting air flow from thepneumatic distribution system to the product tank; and a wear stripremovably mounted on the inner wall of the casing and having a lipextending at least partially over the outlet.
 2. The metering system ofclaim 1 wherein said lip is curved for directing air into the airdiversion path for preventing the air from impeding flow of productthrough the metering system.
 3. The metering system of claim 1 whereinthe wear strip is made of urethane.
 4. The metering system of claim 1wherein fastening notches are provided in the inner wall of the metercasing, said wear strip includes fastening protrusions whichfrictionally engage the notches to secure the wear strip on the innerwall.
 5. The metering system of claim 4 wherein the inner wall of thecasing between the inlet and the outlet is stepped to receive the wearstrip and provide a smooth product path.
 6. The metering system of claim5 wherein the lip of the wear strip is directed toward the meter rollerto define a minimum area in the product path.